The present invention relates to electric power generating windmills, and more particularly, to a windmill having blades with both variable pitch and variable spanwise twist.
For centuries windmills have been used to harness the energy of the wind to grind grain, operate water pumps and drive various other machines. More recently, windmills have been utilized to generate electric power.
The ever increasing cost of energy has led to renewed interest in windmills as a source of electric power. The reliability of windmills, coupled with the fact that they are non polluting, makes them particularly attractive as a partial solution to the energy crisis.
Heretofore, various mechanisms have been utilized to control the operation of windmills. Pivotal supports and wind vanes have been utilized to point windmills into the wind. Governors have been utilized to control windmill rpm. Still, other windmills have incorporated mechanisms for automatically varying the pitch of their blades.
When utilizing a windmill to generate electricity, it is desirable to accommodate fluctuations in wind velocity to insure efficient power generation under most wind conditions. This requires mechanisms for optimizing the aerodynamic properties of the windmill blades.
It is also desirable to eliminate the necessity of utilizing extensive supporting towers in connection with windmills while at the same time insuring against damage under high wind conditions. Preferably, this is accomplished without sacrificing the ability to continuously generate electric power in an efficient manner.